My understanding is the an OCS is an entire Octane scene - and loading such a scene into Poser would not be a valid operation.
How can I import into the plugin a node or collection of nodes that were used in the standalone (ocs files)?
You cannot - the plugin does not read ocs files. Also - I do not understand how you could match the materials in the ocs file with the materials in the Poser scene - since they will most likely have different names.
is there any way that I access the materials that I have already built and collected without re-downloading them from octane live in the plugin?
What sort of materials are you referring to? For skin materials - the recommendation is to use the default skin material node system generated when the plugin converts a scene, or make up your own (http://poserphysics.blogspot.com/2012/11/octanerender-sss-skin-shader.html
), then save the material collection and reload it when you next need a skin shader. For skin materials - you can also copy one skin material and paste it to all other skin materials with a single mouse click.
For non-skin materials, again, the starting point is the automatic material conversion - and you can replace an entire material from the LiveDB.
The power of the copy/paste and import/export is that you can do all of these functions and still keep the original texturemaps. This sort of workflow would not possible if you imported a material from an ocs.
So in summary, whilst there might be initially a small investment creating some materials that you have previously saved in OCS, the faster workflow of copy, paste, import, export, etc should payback this investment many times over.
If there are a large number of people requesting this import functionality, I will look at it. But so far I think yours is only the second request for it.
How many materials are you wanting to import from ocs?
Also, a funny thing happens when I hit return on LiveOctane trying to download a material. Sometimes it sets the Poser Animation on and then I have to stop that before the Octane Window works for me again..
I have noticed this too - and it happens with PoserPhysics and a bunch of other python scripts too. The Poser GUI is somehow picking up an "enter" from the dialog.